Walking beam transfer apparatus

ABSTRACT

A transfer apparatus of the kind using walking beam structures in which traveling articles are moved intermittently in stepwise fashion from a first station toward a second station. The stepping or walking beam is devised in two sections: a first principal liftover element of the beam, and a second leading portion thereof which is extensible from the first main portion. The entire combination of both elements is herein styled a &#39;&#39;&#39;&#39;composite&#39;&#39;&#39;&#39; walking beam. During the walking or liftover operation, transferring articles walk toward the extensible member of the walking beam upon which they are collected and are ultimately bunched together if a sufficiently large number of such articles are so collected. The extension member of the beam structure is adapted to be selectively rapidly advanced or extended from the leading end of the beam apparatus in a relatively rapid fashion so that the extensible beam executes a rapid forward traverse. For this reason, the extensible portion is alternately referred to as a traverse beam or traverse element, and it is linked to control means which automatically initiate the forward traverse at a predetermined point in the walking cycle of the composite liftover beam. The traverse is initiated at such time as a desired number of articles have been collected for quick traverse, en masse, to the object station. The central feature of the structure is the absence of continuous interdigitation of the composite walking beam members with the leaves or fingers of an object table or station. Rather, in the instant disclosure, the composite beam step transfers articles from a source station to a point somewhat short of the object station and then, at predetermined or selected time intervals, groups of articles are darted forwards on the above-mentioned rapid traverse elements, for transfer of the entire article group onto the object station. Then the rapid traverse element is equally rapidly retracted and the normal walkover motion of the composite beam resumes until a collection of objects is again accumulated for a group transfer.

United States Patent [72] inventors Russell L. Race Greenville; DonaldE. Brown, Beldlng, Mlch.

[21] Appl. No 765,392

[22] Filed Oct. 7, 1968 [45] Patented Feb. 23, 1971 [73] Assignee ClarkAutomation, Incorporated Belding, Mich.

[54] WALKING BEAM TRANSFER APPARATUS 9 Claims, 6 Drawing Figs.

Primary ExaminerRichard E. Aegerter Anomey-Wolfe, Hubbard, Leydig, Voit& Osann ABSTRACT: A transfer apparatus of the kind using walking beamstructures in which traveling articles are moved intermittently instepwise fashion from a first station toward a second station. Thestepping or walking beam is devised in two sections: a first principalliftover element of the beam, and a second leading portion thereof whichis extensible from the first main portion. The entire combination ofboth elements is herein styled a composite" walking beam. During thewalking or liftover operation, transferring articles walk toward theextensible member of the walking beam upon which they are collected andare ultimately bunched together if a sufficiently large number of sucharticles are so collected. The extension member of the beam structure isadapted to be selectively rapidly advanced or extended from the leadingend of the beam apparatus in a relatively rapid fashion so that theextensible beam executes a rapid forward traverse. For this reason, theextensible portion is alternately referred to as a traverse beam ortraverse element, and it is linked to control means which automaticallyinitiate the forward traverse at a predetermined point in the walkingcycle of the composite liftover beam. The traverse is initiated at suchtime as a desired number of articles have been collected for quicktraverse, en masse, to the object station. The central feature of thestructure is the absence of continuous interdigitation of the compositewalking beam members with the leaves or fingers of an object table orstation. Rather, in the instant disclosure, the composite beam steptransfers articles from a source station to a point somewhat short ofthe object station and then, at predetermined or selected timeintervals, groups of articles are darted forwards on the above-mentionedrapid traverse elements, for transfer of the entire article group ontothe object station. Then the rapid traverse element is equally rapidlyretracted and the norrna] walkover motion of the composite beam resumesuntil a collection of objects is again accumulated for a group transfer.

PATEIUED FEB 2 3 1971 SHEET 3 OF 4 FIG INVENTORS 004/440 5 50Awv fla,/%M

ATTORNEYS WALKING BEAM TRANSFER APPARATUS BACKGROUND OF THE INVENTIONWalkover transfer mechanisms have been well known for a long time. Suchmechanisms normally employ what is commonly referred to as aninterdigitated system in which walking fingers or beams describe aclosed curve movement between the leaves of a stationary platform forthe conveying articles, namely, a transfer support table. Part of thepath of the finger motion occurs above the support leaves of the table,the other portion being executed below the table. Thus, in a steppingfashion; the beams lift elongate articles in a stepwise fashion alongthe leaves or slats of the support table, from one end thereof towardthe other. The walk beams are interdigitated not only with the tableseats but, one or both beam ends are interdigitated with source and/orobject stations, objects being taken from the source and walkinglyconveyed to the object or delivery station or table. Thus the walking ofthe objects is executed in a continuous stepwise cycle proceeding from asource station toward, and ultimately onto, the object station, whichalso is normally comprised of some sort of elongate article supportingtable or platform.

A particularly appropriate background for the present invention is thatof mechanisms for handling elongate aluminum extrusions. The extrusionindustry experiences special problems in the handling of the extrusionsas they are taken from the extruding dies, inasmuch as they exittherefrom in a most difficult to handle state. The extrusions,immediately upon exiting from the dies, are-normally found in a hot andless than rigid physical state. The extrusions are often relativelylong, thin elements, of channelform cross section, and are in a state ofinternal stress which causes the extrusion to behave in a peculiarfashion. As the extrusions are received from the dies they have apronounced tendency to warp, damage, twist, etc. In order to minimizethis undesirable behavior, the extrusions are handled during thisinitial period with delicacy, in order to allow the extrusions to cool,and in order to avoid agitation of the extruded members during theperiod in which they are so susceptible to the aforementioneddeleterious deformations. Experience has determined that liftoverapparatuses in the nature of those already described, best facilitatethe transfer of such ill-behaved hot extrusions, without unduedeformations thereof, and therefore without the necessity of aninefficient time delay in the conveyance of the extruded articles,allowing them to cool, before transferring.

One objectionable feature, in some applications, is the interdigitationof the walking members of an aforementioned type of apparatus, withsource and/or object platforms. Thus, if such a liftover apparatus isutilized, as it would normally be, to transfer elongate articles in alateral direction from one conveyance or support structure to a secondor object station or platform, the walking beams must walk through theobject platform slats. That is to say the walking beam is normallyinterdigitated with the object platform or table in the same manner inwhich it is interdigitated with the crossover table. In modernindustrial applications, the object platforms are often not simplystationary tables, but instead constitute conveyances of one sort oranother. For example, in specific settings for the present invention,the crossover apparatus is situated for transfer of extruded articlesfrom a runout table (which receives the extrusions from a diehead) to asaw feed table which operates in a direction substantially parallel tothat of the runout table, but at some distance spaced sidewise aparttherefrom. A lateral transfer is necessary to shift the extrusion fromthe runout table to the saw feed table, and the walking apparatus is theexpedient for so doing.

As already mentioned, heretofore known devices for such an applicationnecessitated the interdigitation of the walking apparatus with each ofthe extrusion conveyances (i.e., the runout table and the saw feedconveyance) so that the walking apparatus invaded the runout tables,between the fingers or slats thereof, so as to effectuate a liftoff andredeposit of the extrusions. Walking crossover structures are utilizedfor this transfer operation, for the achievement of a slow, gentle,uniform transfer of the temperamental extrusions. The lateral operationof an interdigitated type of liftover mechanism interferes with therunout operation of the runout tables. An analogous interference occursin the exchange of an extrusion from the walking beam cooling table tothe object table or conveyance (more particularly the saw feed table).In the par ticular case of the saw feed the problem arises as follows:The transversely invading motion of the walking bean structureinterrupts a continuous feeding operation on the saw feed table.

It would be more advantageous to the saw feed operation were it possibleto delay the advancing extrusions on the walking beam apparatus until acomplete sawing operation has been completed. At such time a collectionof extrusions could be exchanged from the walking operation onto the sawfeed table, whereupon the walking beam apparatus would continueadvancing extrusions toward the saw feed conveyance albeit delayingtheir exchange thereto until such is called for by an appropriateinitiating signal. This timing liberates the saw feed conveyance forcontinuous operation without transverse interference from the walkingcrossover apparatus. it is precisely this above-hypothesized apparatuswhich is now provided by invention; and the aforementioned problems areresolved thereby.

SUMMARY OF THE INVENTION My approach to the above-described problem hasbeen to provide auxiliary extensions on the foremost, or leading, endsof the ordinary walking beam structures. The resulting composite" beamsare thus formed in two portions, the foremost or auxiliary element beingextensible from the main element.

The major portion of the time these composite beams operate merely asone single, integral walking beam, with the extrusions advancing towardthe foremost end thereof; however, the foremost extensible portion (thetraverse beam) does not normally project so as to interferingly invadethe region of the receiving saw feed conveyance table. Thus. althoughthe walking beam continuously advances extrusions toward the saw feedconveyance, the extrusions, in this state of operation, do not actuallyreach the saw feed conveyance. Instead, the foremost extension elementsof the walking beams are provided with stop gates, and after sufficientoperation time the advancing extrusions begin to collect against thestop gate and bunch together. At such time as the saw feed table hasbeen cleared, its operation on a group of one or more extrusions beingcompleted, then and only then, a signal is given to the compositewalking beam apparatus to actuate a forward extension of its traversebeam portion: Actuation of the traverse beam effectuates an extension ofthe entire composite walking beam such that the composite beam iseffectively extended to interdigitate with the discontinuous slats ofthe saw feed conveyance. Now, execution of the walking cycle of the beamef fects an exchange of the extrusions collected on the traverse beam,onto the saw feed conveyance. After the liftover, a second signalinitiates retraction of the traverse element of the composite beam sothat it no longer intrudes between the slats or rollers of the saw feedconveyance, but rather resumes collection of extrusions for a subsequentliftover as already described. The saw feed apparatus then proceeds toresume its feeding operation without interruption by the walkingcrossover apparatus. It should be appreciated that the saw feedconveyance is thereby freed more efficiently to operate on a pluralityof extrusions simultaneously. Since a certain time period is necessaryto perform the normal saw feed operation on the extrusions, it isdesirable that the walk-across operation be temporarily interrupted topermit longitudinal saw feeding of the extrusions on the saw feedstructure. It is precisely this beneficial result which may my inventionaccomplishes, while at the same time maintaining the average crossoverrate of extruded members from the runout table to the saw feedapparatus, or other operation stations. It is important also to realizedthat the operator of the saw feed table may, with the system of thisinvention, call for delivery of the aluminum articles at his choosing,and need not be hampered by unwanted interaction of the crossoverequipment.

Accordingly, the objects of my invention are as follows:

To provide an interrupted cycle walk-across apparatus.

To provide walk-across equipment in which deposition of the walkingarticles onto the object station may be delayed for a selected timesequence.

To provide a walk-across structure having an interdigitated walkingapparatus, wherein interdigitation of the walking beam with the objectplatform is intermittent, so as to minimize interruption of theoperation of the object station.

To introduce a extendible walking composite beam crossover apparatusbetween an aluminum extrusion runout table and a secondary operation, inwhich the efficiency of the secondary operation is greatly increased byminimization of its interaction with the crossover mechanism.

To provide an extrusion feed apparatus which greatly increases theefficiency of adjacent cooperating extrusion operations.

The provision of a greatly improved extrusion collecting crossoverapparatus.

A further object of this invention is to reach a nonintegral compositewalking beam construction, in which one element thereof comprises arapid traverse beam.

A still further object of the present invention is to provide anextrusion-collecting device in the form of a rapid traverse beam elementassociated with a normal walking beam element for selected nestingand/or bunching of the advancing extrusions on the walking extrusionconveyance.

Still other objects of the present invention will be apparent from thepresent description, drawings and claims.

IN THE DRAWINGS FIG. 1 is a top plan view of an operative portion of thecomposite walking beam apparatus of the present invention, shown incooperative relation with the object station of an extrusion-receivingconveyance oriented to feed substantially perpendicularly to the walkingbeam mechanism, and shows in broken line the alternate position of thetraverse beam portion of the composite beam.

FIG. 2 is a side elevation view of the apparatus shown in FIG. 1, andincludes a series of aluminum extrusions shown advancing in thedirection of the arrow on the walking beam mechanism, some of which areshown as collected against the stop gate at the end of the traverse beammember of the composite walking beam, and others shown subsequent totheir exchange onto the saw feed table.

FIG. 3 is a sectional view of the apparatus of FIG. 2 taken at sectionline 3-3 thereof and shows the positive belt drive mechanism of anextrusion-receiving conveyance, and more specifically a saw feed tablewhere the upper rollers motivate the extrusions and the belt shown insection is frictionally engaged to drive the rollers by the auxiliaryidlers revolving in the opposite direction below the drive rollers, withthe belt moving in the direction of the arrow. Also seen is the end viewof the composite beam drive structure.

FIG. 4 is a partially broken away sectional view of the presentinvention taken on the line 4-4 of FIG. 3 showing the eccentrics each ofwhich is driven by a separate takeoff chain from the main drive motorsand impart the cyclical walking motion to the composite walking beam;the broken away portion of the figure showing the rack and pinion driveof the traverse beam element; and limit switches being shown, one forinitiation of the traverse beam extension cycle, and the other being forreversal or retraction of the traverse beam.

FIG. Sis a side elevation view of the structure shown in FIG. 4, withthe exception that the walking structure is in the down point of itscycle and the traverse beam is shown in the reversed or retracted partof its cycle having moved back in the direction of the arrow.

FIG. 6 is a sectional view taken on line 6-6 of FIG. 4 and shows insection an end elevation of the composite walking beam apparatus anddepicts the adjacent, separately movable nature of the main beam and thetraversing beam, which fu nction both independently and compositely;also shown are the beam drives, both the eccentric for walking drive andthe shaft-mounted gear drive for the traverse beam.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the figures in FIG.I is seen the general walkover or crossover structure 11, oriented fortransportation of articles toward an object or destination station 13.In this particular case, the object or destination station or platform13 is an aluminum extrusion saw feed table having rollers 15 driven bythe drive belt 17 which is frictionally engaged with each extrusionroller by pressure rollers I9, and which will be better appreciatedlater by reference to FIG. 3.

The general operation of the entire mechanism seen in FIG. I is suchthat extrusions move in the direction of the arrows associated with thephantom line illustration of the walking extrusion A. The ultimatedisposition of the extrusion at position A, is that shown at the phantomline position B, from whence the extrusion is then carried away in thedirection of the arrows shown, in a right-angled relation to thedirection of approach on the walkover device 11. Normally the extrusionis received onto the crossover II from a source station, as a platformor in the setting of the present invention, an extrusion runout table(not shown) which moves the extrusions in their longitudinal directionas they exit from the extruding dies (also not shown). The walkoverapparatus 11 is normally related to the runout table in aninterdigitated fashion, well known to the conveying art with the runouttable oriented substantially parallel to the saw feed table or otherobject station 13, such that the walkover apparatus 11 transports theextrusions in a lateral or sidewise direction between the source andobject stations 13. This also accomplishes an important purpose ofallowing the extrusion to cool while being laterally shifted from therunout table to the saw feed table. This invention, as alreadydescribed, is primarily concerned with the relation between thecrossover cooling table apparatus with the object station as exemplifiedtherein by the saw feed table 13. It should be realized, however, thatthe application need not be limited to aluminumhandling equipment.Moreover various aluminum-handling equipment might be served by thiscrossover apparatus 11, for transferring from extrusionstretching gear,detwisting, or the like, to a storage table, or equipment other than asaw feed.

Only single elements of the crossover cooling table II are shown, forexample, the stationary cross slats 21 and the composite walking beamstructure 23, although both of these structures normally occur ininterdigitated multiplicities, as necessary. The depicted structure ofone composite walking beam 23 between a pair of cross slats 21 iscompletely sufficient for an understanding of the present invention.

Reference is now made to FIG. 2, for a more complete description of theapparatus of FIG. I. Extrusions 25 are seen in spaced relation withtheir direction of motion shown by the arrow across the walkover tableII. The extrusions 25 are seen as supported on the leg 2711-2712 (bestseen in FIG. I) of the two-legged composite beam 23, and shown at a moreadvanced stage by the extrusions 25; nested together against a hingedstock gate 28 at the end of the second leg or traverse beam 29 of thecomposite beam 23. Further advance of the extrusions 25' delivers themto the saw feed table 13 where they rest upon the rollers 15 as shown bythe still nested group of extrusions depicted in the final, crossed-overposition at 25".

The crossover table structure 11 is now to be described in more detail.The crossover structure 11 is supported on vertical legs 31, normallyaffixed to a floor by brackets 32. The stationary cross slats 21 aresupported on the legs 3|, upon the vertical faces of which can be seenpillow block-type bearings 33 in which are journaled the drive shaft 35that delivers the walking motion to composite bean 23 at the main frameportion 27, thereof. Keyed to these shafts 35 are the chain sprockets 37driven by chains 38. FIG. 2 also shows the main drive support structurewhich includes motor base platform 43 and shaft-bracing structure 44. Inactual practice the main drive motor 41 may be substantially offset fromthe positions shown and centered between the sprocket shafts 35. In suchcase (not shown) the moor drive shaft is provided with a specialsprocket and the shaft 40 is independently mounted as a jackshaft on thesupport 44, in the centered position; and an extra sprocket is providedon the jackshaft to be driven by a third chain (not shown) between itand the main drive motor 41. Whether this arrangement, or the one shown,is used is not of contributory importance to an understanding of thepresent invention. l

The saw feed structure is supported on legs 31 and brackets 32. i

The FIG. 5 gives a less cluttered view of the subject matter of FIG. 2,with a chain drive motor structure removed as well as the proximate pairof legs 31; this reveals eccentrics 51 which are mounted to turn onshafts 35 inside the eccentric hanger housings 53. The hanger housing 53depends from, and upwardly supports the main frame 27 of the compositebeam, and it can readily be seen that rotation of shafts 35(synchronized by virtue of their connection to common drive shaft 40)causes the eccentric housing 53 to describe a rotational motion whileremaining in a fixed attitude, because the housing is freely rotatableabout the eccentrically mounted member 51. Thus the composite beam 27describes a substantially circular motion such that composite beam 27oscillates between an advance and a retracted position; as well as anupper and lower position. This can be seen by reference to FIG. 4 (whichshows the walking composite beam in its upper or raised position abovethe stationary slats 21 in heavy line) and FIG. 5 (which shows the loweror descended position below the stationary slats 21 in phantom line).This up-down motion accompanied as it is by a simultaneousadvanceretreat (back and forth) motion of the entire composite walkingbeam structure, clearly lifts any crosswise-disposed free objects fromthe slats 21, advances them some distance and then descends below theslats 21 to redeposit the objects on the crossover table, only to beagain picked up and advanced a short step again as the walking cyclecontinues. Such a walking apparatus as thus far described is presentlyknown to the conveyancing art.

In Fig. 4 is seen an extendible portion 29 of the main walking structure11 which normally cycles in rigid conformance to the cycling of the maincomposite beam structure 27, as though it were an integral portionthereof. Assuming this condition it can be seen that the extensibleportion 29 cycles up and down with respect to the saw feed table, toalternate positions above and below the upper surface of the rollersthereof, as is clearly seen by the previous consecutive reference toFIGS. 4 and 5. FIG. 5 shows the extension or traverse beam 29 belowthesaw feed rollers 15. The saw feed table structure 13 is indented orotherwise open between rollers 15 so as to permit this invasion of thesaw feed table area in the interdigitated fashion which may be bestappreciated by reference again to FIG. 1 which also shows the extensionmember 29, in phantom line, between a pair of the saw feed table rolls15. Thus, normal cycling of the apparatus as already described wouldnormally advance extrusions 25 as seen in FIG. 2 continuously in thespaced-apart relation shown at 25 until they collect on the saw feedtable 13 where they would normally still be spaced apart, unlessnested'by some backstop mechanism, or the like. It is precisely thisfashion in which most known walking beam structures operate.

However, for reasons already described above in Background of theInvention, it is desirable to avoid the continuously interdigitatedrelation between the walking beam structure 11 and the object table orsaw feed structure 13. The main consideration for desiring to eliminatethis feature, is that the operator of the saw feed table may functionmuch more efficiently and economically if the saw feed table can collectone or more extrusions in a bunch and then operate on them in the samefashion without interference or invasion of the saw feed table by thewalking beam. Thus the walking beam may continue cycling and therebyadvancing extrusions 25, yet not invading the saw feed table 13 andthereby leaving it free for continuous uninterrupted saw operation untilsome predetermined time at which it is desired to transfer one or moreof the extrusions 25' from the crossover apparatus to the saw feedtable.

It is just this result that my invention accomplishes by providing acomposite beam in two portions, the main portion 27 with upper supportplatform in two parts 27a and 27b (See FIG. 5) and a second extensiblemember 29 which normally does not invade the saw feed table until suchtime as it is desired by the saw feed operator to deliver additionalextrusions to the saw feed table rolls 15, which have presumably beencleared to receive a new arrival of extrusions. This result isaccomplished by a properly timed extension of the auxiliary portion 29of the composite walking beam, when the saw feed table 13 is preparedfor an additional receipt of extrusions, and at such time as the member29 has collected a sufficient or desired number of extnisions 25', whichnormally would have been collecting in the nested relation shown in FIG.2 against the releasable stop gate 28 (shown projecting upward from theend of the member 29 g The exact timing of the motion of the member 29is as follows: at some pointrwhen the composite structure 27a --27bisat, or very near, to the uppermost point of its walking cycle, themember 29 is rapidly extended forwardly in a direction shown by thearrow in FIG. 4, to the position there shown. This relatively quickforward movement of the member 29 is in the nature of a forward traverseand consequently this member is referred to as a traverse beam 29.Advance of the traverse bean 29 occurs through tripping of the traverseadvance switch 61 which is so mounted to leg 31 (or any other suchstationary structure) so as to be tripped by some cycling portion of thecomposite beam structure such as the eccentric housing 53 (see FIG. 4).Reverse or withdrawal of the traverse beam 29 is initiated by contact ofthe traverse beam structure (e.g. stop gate 28) with the reversingswitch 62 mounted on the cable structure 13. Reversal is as shown in thedirection of the arrow in broken line in FIG. 5, as would be expected,and is delayed slightly so as to permit the walking cycle to carry itcompletely below the upper surface of the rollers 15 prior to theretraction of the traverse beam 29. This permits proper deposit of thearticles, i.e. the extrusions 25", onthe saw feed table 13 without adrag back of these members by the traverse member 29.

Moreover at the same time as the traverse member 29 commences towithdraw from the extension position, the stop gate 28 is released todrop to the lower position as seen in FIG. 5 in broken line. Thisdrop-down of the stop gate 28 also guards against any drag back of theextrusions 25" from the deposit platform, i.e., the rollers 15 of thesaw feed table 13.

A separate reversible drive motor 63 for motivation of the traversebeam, is mounted on the hanger frame 65 from the main frame of thewalking composite beam 27, to which is also supportably connected thetraverse beam drive sprocket 67 on shaft 69. As will be appreciatedother motors or lineal actuators may be used such as hydraulic,pneumatic, or electrical direct drive systems well known in the art.This drive sprocket is driven off from the motor 63 by the drive chain71 com nected to the motor sprocket 72, the drive sprocket 67 having asecondary pinion gear portion 73 which drives the traverse beam 29 to orfro by engagement with the rack portion thereof 75 (see FIG. 4). Theshaft 69 extends to some indeterminate length in either direction fromthe drive sprocket structure so as to connect up with other traversebeam members, depending upon the width of the crossover table, whichwidth conforms substantially to the length of the extrusion membersbeing conveyed or transferred. Similarly of course, the walking shafts35 extend away to connect with other composite walking beam structures(not shown) between other cross slats 21 on the crossover table, thenumber dependent upon the length of extrusions 2 5 served.

Details of the construction for driving the traverse beams are bestappreciated by reference FIG. 6. The sprocket shaft 69 is seen journaledin ball bearing 77 which in turn are mounted in housings 78 attached tothe movable main frame 27 of the composite beam structure. Drive pinion73 is seen engaging the drive rack 75 on the bottom portion of thechannel member 79 into which the traversing support beam 29 is attached.The extrusion-supporting portion of the walking beam is split into twomutually adjustable beam halves 27aand 2717, the second of which istongue and groove fitted into the first and is slidable thereon, in atracked fashion, to any desired point of extension and tightened thereatby the threaded restraining bolt and nut structure 81. One of theseextendible members is slotted (not shown) in which slot the restrainingbolt 81 moves to permit relative motion of the sliding member 270 withrespect to the bolt 81. Comparison of the principal walking supportmember 27a 27b with the traverse beam 29, reveals a slight heightdifferential therebetween (which can be seen by reference to any of theFIG. 1 through 6) which differential is deliberately provided so as tocause only the appropriate selected extrusions 25 to pass to the sawfeed table 13 upon advance of the traverse beams 29.

Both the principal walking support beam 27a 27 b and the traverse beam29 may have upper surfaces formed of a contact layer of graphite (notshown) if desired, so as to provide a superior surface for extrusions 25which are still hot when received from the extruding dies.

Referring again to FIG. 6, it can be seen that the main frame of thewalking beam structure is formed in a split box cross section whichprovides an appropriately sized and designed structure for supportingand partially partially housing the traverse beam drive sprocket 63,shaft 72, bearings etc., all of which must be supportably attached tothe walking structure. Also provided upon the walking beam structure isa forward support roller 83 (see FIG. 4) upon which the forward portionof the traverse beam 29 rests in a level guide frictionless relatron.

Both principal and traverse beam portions are of wood structures whichare separably connected to the metal support channel members 78 and 80respectively.

OPERATION In operation one or more extrusions are alternately lifted andset down by the walking cycle in stepwise fashion proceeding in thedirection of the arrow, and forming a group of extrusions 25 as seen inFIG. 2. Extrusions are, as already described, repeatedly picked up andset down at a somewhat advanced position so as to be forwardly steppedalong on the permanent cross slats 21 of the walkover table structure11. These slats are arranged in a parallel plurality, so as to formracklike stationary structures, the surfaces of which are normallyadapted to receive hot extrusions without interacting with the hotmetal, and may therefore be formed of graphite previously mentioned.This group of extrusions 25 eventually arrives one by one at the end ofthe principal walking platform 27b and transfers onto the traverse beam29, which is seen at d in FIG. 5 to be slightly down stepped from themain walking platform 27a27b, somewhere in the neighborhood of oneeighthinch to one-fourth inch, the purpose of this down step being pointed outbelow. Eventually these advancing extrusions, after passing onto thetraverse beam 29, encounter the stop gate 28 on the end of the traversebeam 29, and as walking motion continues they step together into anested relation of extrusions 25. At the option of the saw feed tableoperator, a switch 61 (see FIG. 4) is tripped which upon the next upcycle of the walking beam apparatus initiates forward traverse of thebeam 29 into the extended position shown.

At the forward limit of the travel of the traverse beam 29 the stop gate28 actuates the second limit switch 62 which initiates reversal of thetraverse motion. Reversal is, however, slightly delayed throughappropriate circuitry so that actual return of the traverse beam doesnot occur until the walking cycle has dropped the beam below the uppersurface of the saw feed rollers 15, as seen in FIG. 5, whereupon theextrusions 25 are there deposited. The traverse beam 29 then retracts,the normal walking cycle having continued all during this traverse beamoperation. The stepdown at d of FIG. 5, referred to previously, assures.that only those extrusions designated 25 (see FIG. 2) will be advancedby the forward travel of the traverse beam 29, whereas if no suchstepdown were present some of the extrusions 25 on the principal walkingplatform 27a27b could be dragged forward by the traverse beam 29. Itshould also be noted that the stop gate 28 flips downwardly as shown inbroken line in FIG. 5, at the appropriate point in the cycle so as toprevent the stop gate from dragging the already deposited extrusions 25"(see FIG. 2) back toward the walkover structure.

Thus, summarizing the sequence of the operation, by reference to FIG. 2,the normal walking structure of the composite walking beam movesextrusions 25 in a steady stepwise progression in the direction of thearrow, the extrusions eventually being moved as a group by the leadingtraverse beam 29 portion of the composite beam until the nested sequenceof extrusions 25' is collected against the stop gate 28. The saw feedoperator may then, by his own manual switch, energize the limit switches61 and 62 so that the traverse beam 29 darts forward when the compositebeam arrives near the upper limit of its walking cycle. The traversebeam 29 then deposits the extrusions 25' into the position as shown at25" on the saw feed rollers 15, as the normal walk cycle progresses. Thelimit switch 62 then causes retraction of the traverse beam 29 toreceive more extrusions 25 as the normal walking cycle continuesuninterrupted.

It should be appreciated that the saw feed operator may call foradditional extrusions at any time he so desires andalso in any number heso desires merely by waiting until the required number of extrusionshave collected on the traverse beam 29. He may even control their degreeof nesting by appropriate timing ofhis request. He is, most importantlyhowever, free all the while to complete his saw feed operation on theextrusions 25 without interdigitated interferring advance of theextrusions and their supporting structures from the crossover apparatusThose familiar with these types of aluminum extrusion handling deviceswill most fully appreciate the advantage inherent in this invention.

Accordingly we have described a transfer apparatus which includes acollecting and traversing structure extendible selectively to move anddeposit collected objects such as extrusions to a separate conveyorstructure moving the entire collected group of objects so collected in adirection transverse to the flow of collected objects.

Having thus described an operative embodiment of our invention, thisdescription will suggest improvements, adaptations, modifications andsubstitutions to those skilled in the art and such improvements,adaptations, modifications and substitutions are intended to be includedwithin the spirit of the present invention, limited only by the scope ofthe hereinafter appended claims.

We claim:

I. In a crossover walking beam transfer apparatus for conveying articlessidewise in continuous stepwise succession toward an article-receivingplatform having separated articlesupporting cross elements, and whereinthe walking transfer apparatus is of the kind embodying at least onewalking beam which is interdigitated between the article-supportingslats of a crossover table (elevated to the level of the platform) torise above and below said slats during said walking cycle; a compositewalking beam construction comprising: a traverse beam member mounted onsaid walking beam in parallel relation thereto for interdigitatedmovement with said walking beam,

said traverse beam member being disposed for longitudinal advancementand retraction in the walking direction relative to said walking beammember, and me ans for selectively advancing and retracting saidtraverse beam relative to said walking beam member so as to effectuatean intermittent extension of said walking beam disposed interdigitallybetween the article support elements of said'article receiving platform,thereby to extend temporarily the limit of the walking operation to saidarticle receiving platform.

2. The apparatus of claim 1 wherein each said walking beam is providedwith track means and said traverse beam is engaged therewith for forwardand backward sliding traverse thereon, with respect to said main walkingbeam.

3. The apparatus set forth in claim 2 wherein the upper,article-supporting surface of said traverse beam is disposed at a lowerlevel than that of the upper, article-supporting surface of theprincipal beam, on said composite walking beams.

4. The apparatus set forth inclaim 3 with the additional structurecomprising: an article stop gate near the free end of said traversebeam, to arrest articles advancing stepwise toward the end of said beam,said gate adapted to be dropped to a lower, nonoperational position, inresponse to actuation of said traverse beam.

5. The apparatus of claim 1 with the additional structure comprisingreversible drive means for said advance and return of said traversebeam.

6. The apparatus recited in claim 5 wherein said traverse beam drivemeans comprise a reversible electric motor supported on said compositewalking beam main frame, and a pinion gear driven by said motor andengaged with a rack on said traverse beam for transmission of traversemotion from said motor to said rack.

7. The apparatus set forth in claim 6 with the further limitation ofcontrol means comprisingzffirst limit switch means actuated by saidwalking beam to initiate the forward traverse motion of said traversebeam when the composite walking beam is approaching the upper limit ofits cycle; second limit switch means actuated near the forward limit oftraverse of said traverse beam to initiate reversal of the traversemotion of said traverse beam, for return thereof; and

third master switch means for energization and deenergization of saidfirst and second limit switch means.

8. The apparatus of claim 7 with the additional limitation comprising:means for dropping said traverse beam stop gate below its normal articlerestraining position; in response to actuation of said first limitswitch means, and restoring said gate to the said normal position inresponse response to actuation of said second limit switch means.

9. In a stepwise conveying process of lineally advancing articles towarda transversely directed receiving station, the method comprising:

advancing articles lineally toward said receiving station with an up anddown stepwise movement;

collecting at a location laterally adjacent the receiving station acontinuous set of the furthest progressed of said advancing articleswhile continuingto transfer other articles with an up and down stepwisemovement;

moving said collected articles up and down in synchronism with the upand down movement of said other advancing articles; selectivelytransporting laterally the entire said collected set of articles ontosaid receiving station during a single up and down cycle of theirmovement without interfering with the lineal advancement of said otherarticles; and

repeating the above two sequences continuously, at time intervalsselected to correspond to a condition of readiness of said receivingstation.

Patent No. 3 565 241 Dated February 23 S 7 Russell L Race et a1Inventor(s) It is certified that error appears in the aboveidentifiedpatent and that said Letters Patent are hereby corrected as shown below:

In the grant (only) insert columns 5 6 7 and 8 cancel the last page.

walking motion to composite bean 23 at the main frame portion 27,thereof. Keyed to these shafts 35 are the chain sprockets 37 driven bychains 38. Fl(.i. 2 also shows the main drive support structure whichincludes motor base platform 43 and sbaft-bracing structure 44 In actualpractice the main drive motor 41 may be substantially offset from thepositions shown and centered between the sprocket shafts 35. in suchcase (not shown) the moor drive shaft is provided with a speeialsprocket and the shaft 40 is independently mounted as a jackshaft on thesupport 44, in the centered position; and an extra sprocket is providedon the juckshaft to he driven by a third chain (not shown) between itand the main drive motor 4|. Whether this arrangement, or the one shown,is used is not ofcontributory importance to an understanding of thepresent invention.

The saw feed structure is supported on legs 31 and brackets 32'.

The FIG. 5 gives a less cluttered view of the subject matter of FIG. 2,with a chain drive motor structure removed as well as the proximate pairof legs 3]; this reveals eccentrics 51 which are mounted to turn onshafts 35 inside the eccentric hanger housings 53. The hanger housing 53depends from, and upwardly supports the main frame 27 of the compositebeam, and it can readily be seen that rotation of shafts 35(synchronized by virtue of their connection to common drive shaft 40)causes the eccentric housing 53 to describe a rotational motion whileremaining, in a fixed attitude, because the housing is freely rotatableabout the eccentrically mounted member 51. Thus the composite beam 27describes a substantially circular motion such that composite beam 27oscillates between an advance and a retracted position; as well as anupper and lower position. This can be seen by reference to FIG. 4 (whichshows the walking composite beam in its upper or raised position abovethe stationary slats 2] in heavy line) and FIG. 5 (which shows the loweror descended position and more efficiently and economically if the sawfeed in collect one or more extrusions in a bunch and then 0p them inthe same fashion without interference or llWi the saw feed table by thewalking beam. Thus llte beam may continue cycling and thereby advancingext 25. yet not invading the saw feed table 13 and thereby it free forcontinuous uninterrupted saw operation uni predetermined time at whichit is desired to transfer more of the extrusions 25' from the crossoverapparatu saw feed table.

it is jUSl this result that my invention accompli: providing a compositebeam in two portions, the mam 27 with upper support platform in twoparts 27:: and 2 HO 5) and a second extensible member 29 which it doesnot invade the saw feed table until such time desired by the saw feedoperator to deliver addition-a sions to the saw feed table rolls l5,which have pres been cleared to receive a new arrival of extrusions. This accomplished by a properly timed extension ofthe a portion 29 of thecomposite walking beam, when the 5 table I3 is prepared for anadditional receipt of ext and at such time as the member 29 hascollected a suffi desired number of extrusions 25', which normally wotbeen collecting in the nested relation shown in FIG. 2 the releasablestop gate 28 (shown projecting upward f end ofthe member 2) i.

The exact tinting of the motion of the member 29 i lows: at some pointwhen the composite structure 270 at, or very near, to the uppermostpoint of its walkin the member 29 is rapidly extended forwardly in a dshown by the arrow in HO. 3, to the position there This relatively quickforward movement of the memt in the nature of a forward traverse andconscqucr member is referred to as a traverse beam 29. Advanc traversebean 29 occurs through tripping of the trav Patent No. 3 56S 241 Inventr( Russell L.

Race et a1.

Dated February 23 1971 PAGE 2 It is certified that error appears in theabove-identified patent: and that said Letters Patent are herebycorrected as shown below:

below the stationary slats 21 in phantom line). This up-down motionaccompanied as it is by a simultaneous advancerctrcat (back and forth)motion ofthe entire composite wall;- ing beam structure. clearly liftsany crosswise-disposed free objects from the slats ll, advances themsome distance and then descends below the slats 21 to redeposit theobjects on the crossover table. only to be again picked up and advanceda short step again as the walking cycle continues. Such a wall;- ingapparatus as thus far described is presently known to tire conveyancingart.

In Fig. 4 is seen an cxtendiblc portion 29 of the main walking structureIt which normally cycles in rigid conformance to the cycling of the maincomposite beam structure 27. as though it were an integral portionthereof. Assuming this condition it can be seen that the extensibleportion 19 cycles up and down with respect to the saw feed table toalternate positions above and below the upper surface of the rollers l5thereof, as is clearly seen by the previous consecutive reference toNUS. 4 and 5 HO. 5 shows the extension or traverse beam 29 below the sawfeed rollers 15. The saw feed table structure 13 is indented orotherwise open between rollcrs [5 so as to permit this invasion of thesaw feed table area in the interdigitated fashion which may be bestappreciated by reference again to FIG. I which also shows the extensionmember 29. in phantom line, between a pair of the saw feed table rolls15. Thus. normal cycling ofthe apparatus as already described wouldnormally advance extrusions as seen in FIG. 2 continuously in thespaced-apart relation shown at 25 until they collect on the saw feedtable I. where they would normally still be spaced apart. unless-nestedby some backstop mechanism or the like. It is precisely this fashion inwhich most known walking beam structures operate.

However. for reasons already described above in Background of theInvention. it is desirable to .HDltl the continuously interdiyitiitedrelation between the walking beam structure ll and the ob ect lLlbiL' orsaw feed structure L3. The

main consideration for desiring to eliminate this feature. is that theoperator of the saw t'ccd table may function much vance switch 6| whichis so mounted to leg 31 (or an such stationary structure) so as to betripped by some portion of the composite beam structure such as thc cchousing 53 (sec l 'lti. 4 Reverse or withdrawal oftlie t beam 29 isinitiated by contact of the traverse beam s'i [c.g. stop gate 28) v-rththe rcserring switch 61 mour the cable structure U. Reversal is as shownin the direi. the arrow in brolzen line in HO. 5, as would be expecti isdelayed slightly so as to permit the walking cycle to i completely belowthe upper surface of the rollers l5 t the retraction of the traversebeam 29. This permits deposit of the articles, ie. the estrusions 2. onthe s: table [3 without a drag back of these members by the ti member29.

Moreover at the same time as the traverse member 2 mences to withdrawfrom the extension position, the sti Z8 is released to drop to the lowerposition as seen in Fl broken line. This drop-down of the stop gate 28also against any drag brick of the extrusions 25" from the 1 platform.i.e.. the rollers 15 otthe saw feed table l3 A separate reversible drivemotor 63 for motivation traverse beam. is mounted on the hanger frame 65to main frame ofthc walking composite beam 27, to which supportablyconnected the traverse beam drive sprocLc shaft (:9. As will beappreciated other motors or lineal tors may be used such .is' hydraulic,pneumatic, or cli. direct drive systems well known in the art. filthdrive sp is driven off from the motor 63 by the drive chain 7 nected tothe motor sprocket 72, the drive sprocket (17 a secondary pinion gearportion 73 which drives the ti beam 2) to or fro by engagement with therack portioiit 75 (sec l{l(l. 4). The shaft 6) extends to somettltiLlt'r length in either direction from the time procket stint as toconncct up with other traverse lrcam members. d log upon the width ofthe crossover table, which with forms substantially to the length oftlic eiitrusiori lllt being conveyed or transferred. Srrriil-iily ofcourse, tlii iiig shafts 35 extend away to connect with other con PatentNo. 3 56S 241 Dated February 23, 1971 Inventor(s) Russell L. Race et:11.

PAGE 3 It is certified that error appears in the above-identified patentand that said Lett.fe rs Patent: are hereby corrected as shown below:

walking beam structures (not shown) between other Cttts's slats 21 onthe crossover table. the number dependent upon the length of extrmions25served.

m f h construction for tlnvtnt! the traverse beams e best appreciated byreference l-lti. 6. The sprocket shall 69 is seen jonrnnled in ballbeartnp 77 which in turn are mounted in housings 78 attached to themovable main frame 27 of the composite beam structure. Drive pinion 73is seen ping the drive rack 75 on the bottom portion of the channclmember 79 into which the traversing support beam 2) is attached. Theextrusion-supportrnp portion of the walking beam is split into twomutually itc'lJUSlillilC beam halves 27uand 27!), the second of which istongue and groove fitted into the first and is slidahle thereon. in atrucked fashion, to any desired point of extension and tightened thereatby the threaded restraining bolt and nut structure 8]. One of thesectrtcndible members is slotted (not shown) in which slot the restrainingbolt 8] moves to permit relative motion of the sliding member 27a withrespect to the bolt 8]. Comparison of the principal walking supportmember 27:; -27b with the traverse beam 29, reveals a slight heightdifferential lherebctween (which can be seen by reference to any of theFIG. I through 6) which differential is deliberately provided so as tocause only the appropriate selected extrusions 25' to pass to the sawfeed table [3 upon advance of the traverse beams 29.

Both the principal walking support beam 27:: -27 band the traverse beam29 may have upper surfaces formed of a contact layer of graphite (notshown) if desired. so as to provide a superior surface for extrusions 25which are still hot when received from the extruding dies.

Referring again to FIG. 6, it can he seen that the main frame of thewalking beam structure is formed in a split box cross section whichprovides an appropriately sized and designed structure for supportingand partially partially housing the traverse beam drive sprocket 63,shaft 72, bearings etc., all of which must be supporfahly attached tothe walking structure. Also prmidcd upon the walking beam structure is aforward support roller 83 (see FIG. 4) upon which the forward portion ofthe traverse beam 29 tests in a level guide frictionless relation.

Both principal and traverse beam portions are of wood structures whichare separnbly connected to the metal support channel members 78 and 80respectively.

At the forward limit of the travel of the traverse b the stop pate 28nctuates the second lirmt switch 62 w itiates reversal of the traversemotion. Reversal is, hi slightly delayed tlnough appropriate circuitryso that return of the traverse beam does not occur until the cycle hasdropped the beam below the upper surtact saw feed rollers 15. as seen inHG. 5. whereupon thr sions 25' are there deposited The traverse beam 1retracts, the normal walking cycle having continued all this traverselieam operation. The stepdown at d of referred to previously. assuresthat only those ext designated 25 (see FIG. 2) will be advanced by the 1travel of the traverse beam 29. whereas if no such str were present someof the extrusions 25 on the princtp; irig platform 27u-27b could bedragged forward traverse beain 29. It should also he noted that the stopfhps downwardly as shown in broken line in H0. 5. at propriate point inthe cycle so as to prevent the stop git dragging the already depositedextrusions 25" (see I back toward the walkover structure.

Thus. summarizing the sequence of the operati reference to FIG. 2, thenormal walking structure of n postte walking beam moves extrusions 25 ina steady s progression in the direction of the arrow, the extrusiontually being moved as a group by the leading traverse b portion of thecomposite beam until the nested sequi extrusions 15 is collected againstthe stop gate 28. "l feed operator may then, by his own manual switch, ethe limit switches 61 and 62 so that the traverse beam 2 forward whenthe composite beam arrives near the upp of its walking cycle. Thetraverse beam 29 then depu extrusions 25' into the position as shown at25" on I feed rollers 15. as the normal walk cycle progresses. Tl switch62 then' causes retraction of the traverse bean receive more extrusions25 as the normal walking cyc tinues uninterrupted.

it should be appreciated that the saw feed operator n for additionalextrusions at any time he so desires and any number he so desires merelyby waiting until the r1 number otextrusions have collected on thetraverse be He may even control their degree of nesting by appr timingofhis request. He is, most importantly however. the while to completehis saw feed operation on the ext 25' without intcrdigitatedinterfcrring advance of the sions and their supporting structures fromthe crosso UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PatentNo. 3 1 I 241 Dated F b Z3 1 92] Russell L. Race et a1 PAGE 4Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letters Patent; are hereby corrected as shownbelow:

OPERATION In operation one or more extrusions are alternately lifted andset down by the walking cycle in stepwise fashion proceeding in thedirection ofthe arrow, and forming a group ofextrusions 25 as seen inFIG. 2. Extrusions are, its already described, repeatedly picked up andset down at a somewhat advanced position so its to be forwardly steppedalong on the permanent cross shits 21 of the walkover table structurell. These sluts are arranged in a parallel plurality, so as to formtacklilte stationary structures. the surt'aces of which are normallyadapted to receive hot extrusions without interacting with the hotmetal, and may therefore he formed of graphite previously mentioned.This group of extrusions 25 eventually arrives one by one at the end ofthe principal walking platform 27b and transfers onto the traverse beam29, which is seen at r! in FIG. to be slightly down stepped from themain walking platform 27a27h, somewhere in the neighborhood of one-:ighth inch to one-fourth inch, the purpose of this down stop beingpointed out hLlOW. Eventually these advancing extrusions, after passingonto the traverse beam 2), encounter the stop gate 28 on the end ol thetraverse lit-urn 2), and AS walking motion continues they step toyetherinto a nested relation ofextrusions At the option of the saw Iced trihleoperator, at switch (-l (st-e Hti. 4) is tnpped which upon the next upcycle of the Wtlihlllfl hcnrn llpptll'illtlfi initiates t'orwurdtraverse 0f the beam 29 into the extended position shown.

8 paratus Those familiar with these types utultirninum c handlingdevices will most fully appreciate the advau herent in this invention.

Accordingly we have described a transfer appurutt includes a collectingand traversing structure extendih tively to move and deposit collectedObjLClS such as U to a separate conveyor structure moving the entire cgroup of objects so collected in a direction transs-er: flow ofcollectedobjects Having thus described an operative embodiment o vention, thisdescription will suggest improvements. lions, modifications 21ndsubstitutions to those skilled l and such improvements, adaptations,modifications a stitutions are intended to be included within the spirpresent invention, limited only by the scope ofthe he: appended claims.

We claim:

l. in a crossover walking heum transfer apparatus veying articlessidewise in continuous stepwise sui toward an itl'ItClC-IL'LCIVIIIE!platform having separated supporting cross elements, and when-in thewalking apparatus is of the kind embodying at lcmt one Wlllhll which I\'llllll'tllfjllllfltl between the uiticle-supportin a crossover tnhlc(elevated to the level ol the plntlorni above and below said sl.itduringsaid \vzillun g Cyclev posits walking henni construction comprisingattrdtt-r member mounted on said walking henni tn pntttlh-l thereto forinterdigitnted movement with snid wnlhin Signed and sealed .this 7th dayof December 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. Attesting Officer ROBERT GOTTSCHALK ActingCommissioner of Pat

1. In a crossover walking beam transfer apparatus for conveying articlessidewise in continuous stepwise succession toward an article-receivingplatform having separated article-supporting cross elements, and whereinthe walking transfer apparatus is of the kind embodying at least onewalking beam which is interdigitated between the article-supportingslats of a crossover table (elevatEd to the level of the platform) torise above and below said slats during said walking cycle; a compositewalking beam construction comprising: a traverse beam member mounted onsaid walking beam in parallel relation thereto for interdigitatedmovement with said walking beam, said traverse beam member beingdisposed for longitudinal advancement and retraction in the walkingdirection relative to said walking beam member, and means forselectively advancing and retracting said traverse beam relative to saidwalking beam member so as to effectuate an intermittent extension ofsaid walking beam disposed interdigitally between the article supportelements of said article receiving platform, thereby to extendtemporarily the limit of the walking operation to said article receivingplatform.
 2. The apparatus of claim 1 wherein each said walking beam isprovided with track means and said traverse beam is engaged therewithfor forward and backward sliding traverse thereon, with respect to saidmain walking beam.
 3. The apparatus set forth in claim 2, wherein theupper, article-supporting surface of said traverse beam is disposed at alower level than that of the upper, article-supporting surface of theprincipal beam, on said composite walking beams.
 4. The apparatus setforth in claim 3 with the additional structure comprising: an articlestop gate near the free end of said traverse beam, to arrest articlesadvancing stepwise toward the end of said beam, said gate adapted to bedropped to a lower, nonoperational position, in response to actuation ofsaid traverse beam.
 5. The apparatus of claim 1 with the additionalstructure comprising reversible drive means for said advance and returnof said traverse beam.
 6. The apparatus recited in claim 5 wherein saidtraverse beam drive means comprise a reversible electric motor supportedon said composite walking beam main frame, and a pinion gear driven bysaid motor and engaged with a rack on said traverse beam fortransmission of traverse motion from said motor to said rack.
 7. Theapparatus set forth in claim 6 with the further limitation of controlmeans comprising: first limit switch means actuated by said walking beamto initiate the forward traverse motion of said traverse beam when thecomposite walking beam is approaching the upper limit of its cycle;second limit switch means actuated near the forward limit of traverse ofsaid traverse beam to initiate reversal of the traverse motion of saidtraverse beam, for return thereof; and third master switch means forenergization and deenergization of said first and second limit switchmeans.
 8. The apparatus of claim 7 with the additional limitationcomprising: means for dropping said traverse beam stop gate below itsnormal article restraining position; in response to actuation of saidfirst limit switch means, and restoring said gate to the said normalposition in response response to actuation of said second limit switchmeans.
 9. In a stepwise conveying process of lineally advancing articlestoward a transversely directed receiving station, the method comprising:advancing articles lineally toward said receiving station with an up anddown stepwise movement; collecting at a location laterally adjacent thereceiving station a continuous set of the furthest progressed of saidadvancing articles while continuing to transfer other articles with anup and down stepwise movement; moving said collected articles up anddown in synchronism with the up and down movement of said otheradvancing articles; selectively transporting laterally the entire saidcollected set of articles onto said receiving station during a single upand down cycle of their movement without interfering with the linealadvancement of said other articles; and repeating the above twosequences continuously, at time intervals selected to correspond to acondition of readiness of said receiving station.